Vehicles, such as rail vehicles, include power sources, such as diesel engines. In some vehicles, fuel is provided to the diesel engine by a common rail fuel system. One type of common rail fuel system comprises a low-pressure fuel pump in fluid communication with a high-pressure fuel pump, and a fuel rail in fluid communication with the high-pressure fuel pump and further in fluid communication with at least one engine cylinder. The high-pressure fuel pump pressurizes fuel for delivery through the fuel rail. Fuel travels through the fuel rail to at least one fuel injector, and ultimately to at least one engine cylinder where fuel is combusted to provide power to the vehicle. In order to reduce the likelihood of engine degradation, the common rail fuel system may be monitored for fuel leaks.
In one approach, the common rail fuel system detects fuel leaks by positioning a liquid sensor in an exterior wall of a double-walled conduit. If a crack occurs in an inner wall of the double-walled conduit, fuel enters a cavity between the inner wall and the outer wall through the crack. Fuel fills the cavity until it is detected by the liquid sensor, at which point a fault is triggered that indicates a fuel leak.
However, the inventors herein have identified issues with the above described approach. For example, the liquid sensor is merely capable of detecting fuel leaks in the double-walled conduit. If a fuel leak occurred elsewhere in the common rail fuel system, such as through a fuel injector nozzle or a fuel injector control path, it would not be detected by the liquid sensor. Moreover, the addition of the liquid sensor to detect fuel leaks increases production costs and design complexity of the fuel system. Additionally the above described approach is merely applicable to a double-walled configuration, and would not work properly if implemented in a single-walled configuration.